Wind and rainfall warnings have been issued for counties across the country.
A status yellow rainfall warning for Munster, Dublin, Carlow, Kilkenny, Wexford, Wicklow, Galway and Mayo comes into effect from 2am on Tuesday morning.
20-30mm is expected to fall over a short period, with a warning of some surface flooding.
Higher totals of rainfall are expected in mountainous areas.
The warning is valid until 2pm on Tuesday afternoon.
Meanwhile, a wind warning will come into effect for Munster, Dublin, Carlow, Kilkenny, Wexford, Wicklow, Donegal, Galway, Leitrim, Mayo and Sligo from 3am tomorrow morning.
Wind Warning Issued
Status: Yellow
Location: Munster, Dublin, Carlow, Kilkenny, Wexford, Wicklow, Donegal, Galway, Leitrim, Mayo and Sligo
Valid: Tuesday 3am to 3pm
Warning info: https://t.co/ozrQHtoOkt pic.twitter.com/d2SHadxP3G— Met Éireann (@MetEireann) November 26, 2018
Forecasters say mean speeds of 50-65km/hr with gusts from 90-100km/hr are expected, possibly higher along exposed coasts.
The status yellow warning will be valid until 3pm tomorrow.
It comes as forecasters warn that unsettled weather is on the way as Storm Diana heads towards the country across the Atlantic.
The worst of the wind and the rain is expected on Wednesday, but Met Éireann says conditions will deteriorate from tonight.
Forecaster Matthew Martin explained: "[Storm Diana] will move towards Ireland on Wednesday, but at that stage it will be becoming a little less intense.
"We aren't expecting anything too severe, but we are monitoring it very closely."
